A tunnel device for an input/output node of a computer system. A tunnel device
includes a first interface, a second interface and a control unit. The first interface
may receive a plurality of data bytes associated with a command packet on a first
external input/output bus. The second interface may be coupled to the first interface
by an internal data path configured to convey up to a maximum number of data bytes
in a given cycle. The control unit may be coupled to control the conveyance of
the data bytes from the first interface to the second interface upon the internal
data path. The first interface may further align the smaller number of data bytes
on a corresponding number of designated bits of the internal data path with no
intervening invalid data bytes when conveying a smaller number of data bytes than
the maximum number of data bytes.
